The present invention relates to a stereo demodulation device and, more particularly, to a stereo demodulation device including an audio muting circuit.
A PLL (Phase Locked Loop) multiplex demodulating IC (Integrated Circuit) is used in a conventional FM stereo receiver. Along with the multifunctions of conventional FM stereo receivers, a pilot canceller, a separation adjuster, an active filter, and an audio output muting circuit have been included in recent models. Because of this, adjustment positions and control terminals are required for the respective functions. For example, a conventional stereo demodulator with pilot cancel and audio muting functions requires two terminals, i.e., a pilot cancel signal generation terminal and a pilot cancel setting terminal. The number of pins in a stereo demodulation IC is thus increased. When additional functions such as a pilot canceller function are added to an IC, adjustment and control terminals are inevitably increased. As a result, the number of pins of the IC package becomes limited and the resultant IC becomes expensive.